title: Alleviation of osmotic stress effects by exogenous application of salicylic or abscisic acid on wheat seedlings.
abstract: The aim of the study was to assess the role of salicylic acid (SA) and abscisic acid (ABA) in osmotic stress tolerance of wheat seedlings. This was accomplished by determining the impact of the acids applied exogenously on seedlings grown under osmotic stress in hydroponics. The investigation was unique in its comprehensiveness, examining changes under osmotic stress and other conditions, and testing a number of parameters simultaneously. In both drought susceptible (SQ1) and drought resistant (CS) wheat cultivars, significant physiological and biochemical changes were observed upon the addition of SA (0.05 mM) or ABA (0.1 μM) to solutions containing half-strength Hoagland medium and PEG 6000 (-0.75 MPa). The most noticeable result of supplementing SA or ABA to the medium (PEG + SA and PEG + ABA) was a decrease in the length of leaves and roots in both cultivars. While PEG treatment reduced gas exchange parameters, chlorophyll content in CS, and osmotic potential, and conversely, increased lipid peroxidation, soluble carbohydrates in SQ1, proline content in both cultivars and total antioxidants activity in SQ1, PEG + SA or PEG + ABA did not change the values of these parameters. Furthermore, PEG caused a two-fold increase of endogenous ABA content in SQ1 and a four-fold increase in CS. PEG + ABA increased endogenous ABA only in SQ1, whereas PEG + SA caused a greater increase of ABA content in both cultivars compared to PEG. In PEG-treated plants growing until the harvest, a greater decrease of yield components was observed in SQ1 than in CS. PEG + SA, and particularly PEG + ABA, caused a greater increase of these yield parameters in CS compared to SQ1. In conclusion, SA and ABA ameliorate, particularly in the tolerant wheat cultivar, the harmful effects and after effects of osmotic stress induced by PEG in hydroponics through better osmotic adjustment achieved by an increase in proline and carbohydrate content as well as by an increase in antioxidant activity.
authors.affiliation: The F. Górski Institute of Plant Physiology, Polish Academy of Sciences, Kraków 30-239, Poland. i.marcinska@gmail.com.
authors.forename: Izabela
authors.initials: I
authors.lastname: Marcińska
authors.forename: Ilona
authors.initials: I
authors.lastname: Czyczyło-Mysza
authors.forename: Edyta
authors.initials: E
authors.lastname: Skrzypek
authors.forename: Maciej T
authors.initials: MT
authors.lastname: Grzesiak
authors.forename: Franciszek
authors.initials: F
authors.lastname: Janowiak
authors.forename: Maria
authors.initials: M
authors.lastname: Filek
authors.forename: Michał
authors.initials: M
authors.lastname: Dziurka
authors.forename: Kinga
authors.initials: K
authors.lastname: Dziurka
authors.forename: Piotr
authors.initials: P
authors.lastname: Waligórski
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Juzoń
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Cyganek
authors.forename: Stanisław
authors.initials: S
authors.lastname: Grzesiak
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology; D009997:Osmotic Pressure; D020156:Salicylic Acid / Q000494:pharmacology; D036226:Seedlings / Q000187:drug effects; D014908:Triticum / Q000187:drug effects
chemical_list: D000040:Abscisic Acid; D020156:Salicylic Acid